[FFmpeg-user] Copying ARIB captions does not work

[Jakub Vojáček]

On Mon, May 13, 2019 at 3:45 PM Moritz Barsnick <barsnick at gmx.net> wrote:

> On Mon, May 13, 2019 at 13:00:20 +0200, Jakub Vojáček wrote:
> > The captions are recognized on the input but no longer recognized on the
> > output. Should that be supported? We have been doing the same thing with
> > dvb_subtitles and it worked as expected but doesn't work with arib.
> [...]
> > Input #0, mpegts, from 'test_copy.ts':
> >   Duration: 00:05:00.70, start: 1.400000, bitrate: 16128 kb/s
> >   Program 1
> >     Metadata:
> >       service_name    : Service01
> >       service_provider: FFmpeg
> >     Stream #0:0[0x100]: Video: h264 (High) ([27][0][0][0] / 0x001B),
> > yuv420p(tv, bt709, top first), 1920x1080 [SAR 1:1 DAR 16:9], 29.97 fps,
> > 29.97 tbr, 90k tbn, 59.94 tbc
> >     Stream #0:1[0x101](por): Audio: aac_latm (HE-AAC) ([17][0][0][0] /
> > 0x0011), 48000 Hz, stereo, fltp
> >     Stream #0:2[0x102](eng): Audio: aac_latm (HE-AAC) ([17][0][0][0] /
> > 0x0011), 48000 Hz, 5.1, fltp
> >     Stream #0:3[0x103]: Data: bin_data ([6][0][0][0] / 0x0006)
> > [@1557745032]: Unsupported codec with id 100359 for input stream 3
>
> If I see ffmpeg's code correctly, ffmpeg has the capability to demux
> (and decode, using libaribb24) ARIB captions, but it does not have the
> capability to mux them correctly. Therefore your "copy codec" remuxing
> loses the properties in the resulting MPEG-TS.
>
> I may be wrong, this is my interpretation of how ARIB works and what's
> happening.
>
> Regards,
> Moritz
>

Thank you for the information. Do I understand correctly that converting to
some other format, such as dvb_subtitles, is not supported? Do you know if
there any plans to add support for muxing ARIB captions?

Thank you again
Jakub